1. Field of the Invention
The present invention relates to a semiconductor memory and a process for manufacturing the same, and more particularly to a semiconductor memory used as a main memory provided on a group of small size personal apparatuses such as notebook-type computers, notebook-type word processors and handy terminals of palm top personal computers and to a process for manufacturing the same.
2. Description of the Prior Art
Conventional main memories incorporated in small-size personal apparatuses have been manufactured by forming a mask ROM and a RAM into one chip to be provided thereon.
Programming mask ROMs on the development stage involves considerable inconvenience for users such as prolonged period of development and the impossibility of revising data.
Although forming an EEPROM and a RAM into one chip to be provided on systems for electrically erasing and writing in data without programming on the development stage is reported, EEPROMs have such drawbacks as limited time of rewriting data and considerable time required for one cycle of rewriting (10 msec/cell), thereby making it very difficult to provide a large capacity.